Fire Meet Gasoline
by IMTrinity
Summary: "Maybe you could fight the mark for years, maybe centuries like Cain did. But you cannot fight it forever, and when you finally turn, and you will turn, Sam and everyone you know, everyone you love, they could be long dead. Everyone except me. I'm the who'll have to watch you murder the world..."


_A/N:_ The idea for this fic came straight from Castiel's conversation with Dean from 10.22. So hopefully everyone who reads this watched not only that episode but all the ones dealing with the Mark of Cain because SPOILERS. Also, this is Destiel Slash, just a warning...Enjoy!

* * *

 _It's dangerous to fall in love_

 _But I want to burn with you tonight_

 _Hurt me_

 _There's two of us_

 _Bristling with desire_

 _The pleasure's pain and fire_

 _Burn me_

 _So come on_

 _I'll take you on, take you on_

 _I ache for love, ache for us_

 _Why don't you come_

 _Don't you come a little closer_

 _So come on now_

 _Strike the match, strike the match now_

 _We're a perfect match, perfect somehow_

 _We were meant for one another_

 _Come a little closer_

 _Flame you came to me_

 _Fire meet gasoline_

 _Fire meet gasoline_

 _I'm burning alive_

 _I can barely breathe_

 _When you're here loving me_

 _Fire meet gasoline_

 _Fire meet gasoline_

 _I got all I need_

 _When you came after me_

 _Fire meet gasoline_

 _I'm burning alive_

 _And I can barely breathe_

 _When you're here loving me_

 _Fire meet gasoline_

 _Burn with me tonight_

- _Fire Meet Gasoline_ , Sia

* * *

It's a dance. One leads while the other tries to follow, circling, always, and never really getting anywhere. Then the music ends, and the moment is over. You move on. Or your partner does. You are left there, standing awkwardly, until a new dance ensues. And the process starts all over again.

Castiel inwardly curses as he comes to a halt, perfectly aware of his missed opportunity. The pulse flutters deep within, a reflexive action that he can hardly control. Despite his immortality, the visage he wears always seems to remind him just how fragile the human body can be. Well, most humans.

The sky is dark above him; a storm moves in quickly, speeding until there is nowhere to go. He allows the soaking water to envelope him. It's not like he can catch cold.

The long-abandoned gas station is the closest and he tears the door nearly off its rusted hinges as he steps inside. He dries his clothing in an instant and stares out the cloudy windows in disdain. There are days when he feels completely useless, aimlessly chasing after shadows and ghosts.

He wishes it was that simple. Ghosts he can deal with, demons he can handle. This seems above him.

* * *

The blood coating his hands and the cuffs of his favorite shirt don't bother him. It's the smell that always gets to him. The same, metallic tang that is shared by humans and animals alike. It fills his nostrils and sends him scrambling to the nearest source of water. He feels much better afterwards.

Dean doesn't do that now, though. He crouches down instead and carefully wipes his hands across the shirt of the dead man at his feet. He sniffs absently, cracking his neck left, then right, and finally stands when most of the blood has been wiped off. He doesn't spare the body another glance. He does however rummage through the pockets of the dead man, grinning when he finds the thick wallet. He grabs the bills, swipes all the cards and chucks the square bit of leather across the room.

His thirst sated, he whistles as he walks out, eyes ahead and not on the darker figure lurking nearby.

* * *

He hasn't spoken to anyone in decades. Well, he has spoken to Dean, though he refuses to dwell on any of those conversations. They weren't what you'd call 'productive'. Still, he sometimes misses the simplicity of conversation. He remembers long talks with Sam, when he was still able to speak and remember. He'd sit by his bedside and regal the younger Winchester with stories of his own past. Sam was fascinated with anything history related. Castiel would talk for hours about old Jerusalem or Constantinople. Hundreds of years ago. Thousands.

He didn't like to talk of Heaven too much, though. His time as a soldier was bittersweet and anything that came afterwards was not vital to him. Save for meeting the Winchesters. He's still not sure if it was a blessing or a curse.

There is no Sam to talk with now. There's nothing but his own thoughts.

* * *

It's like an itch he can't scratch. Gnawing at him, terrorizing him. He'd go insane if he already wasn't. He would have killed Cas decades ago if not for the fact that the angel is the only being who knows where the First Blade is. It's not like he needs it or anything, but the damned mark always seems to ache for it. He certainly wouldn't mind clamping his fingers around that beauty again.

Over the long years he's used a variety of weapons at his disposal. Knives, machetes, a flamethrower once. His own fists-a personal favorite. There just isn't anything like feeling bone break underneath one's fist. And right now his fists clench automatically, and he can practically smell the winged freak around. He smirks to himself. Well, _winged_ would be an incorrect description. What kind of angel doesn't have wings?

He's not really fooling himself or anything. He knows Cas could have ended him a million times over by now. He's not stupid. But neither is Cas. He knows exactly what'll happen to Dean if he dies. Big black eyes, and everything that comes with it.

There was a time that prospect would have frightened him. He can't remember it. He can't really remember much from his past. It's sort of a blessing, really. Why dwell on things? There's so much more out there for him.

He has an endless amount of energy and stamina and isn't burdened by the necessities most humans face. He's hardly aware of the changes sprouting up around him. None of it matters. People stay the same, no matter how much the world changes. He clenches his fists tighter.

* * *

Castiel can go for months without interfering. First of all, tracking Dean down is sometimes problematic. It's not like he can call him. But there are always trails to follow. Sightings and horror tales, eyewitness accounts. Most of the time he comes too late. The carnage that usually greets him is for his benefit, he soon comes to realise.

Dean enjoys his work. He's perfected the art of chaos and he's showing it off for the world to see. Well, mostly it's for Cas. It's like he enjoys riling him up, purposely choosing the most heinous of butchery to display his work of art.

He frowns in dismay at the latest victim. If not for the clothing, the sex would be entirely unrecognizable. There's not a clean spot to stand on and even the police seem queasy to be lurking next to something so foul.

His thoughts gather to a conversation he'd had, many moons ago.

"This is beneath you, Dean. Even Cain didn't relish in his kills. You've sunk to depths I couldn't even fathom."

"Maybe you never knew me as well as you thought you did. In fact, you should quit pretending you even knew me at all. Leave. Go back home. Just get the fuck out of my way."

It was nearly always the same, just with different vocabulary and curses.

* * *

The mark's hold on him is absolute. The few seconds of clarity he used to get are all but gone, erased, just like the old Dean. He loves the power flowing through his veins. He loves not caring. It's like the mark is feeding off his soul, devouring it until there's nothing left.

He doesn't feel different, physically. When he bothers to glance in a mirror he still recognizes his face, though his eyes are different and he's got a few more grays. Still, he figures if he were going to die, it would've happened by now. He doesn't need to ask Cas if he's immortal. He would have laughed at that forever ago. Now, it's just his life.

He finds a piece of shit trying to rape some girl in some alley and his blood boils deliciously. He's on the guy before he knows what's going on, breaking his neck in one move. The crunch makes a satisfying sound. The girl is weeping on the cold cement but he hardly pays any attention to her, his powerful grip still holding on to the corpse.

She's muttering her thanks in between sobs and he harshly tells her to get the fuck out and when she's out of sight he lowers the body to the ground and places his thumbs in the guy's eye sockets and _presses_. It's not as cool as he thought it would be. Still… He wipes his hands on his jeans and walks away.

* * *

Castiel kneels on the soft, dewy grass, hands clearing away the dry, cracking leaves and random twigs, until just a stone marker is revealed. The letters S and W are beginning to fade but he doesn't mind. It was never intended to be permanent, just a place to gather his thoughts.

It wasn't Dean that gingerly carried the body of his brother to the pyre. It wasn't Dean that laid out the wood and stood there watching until the last embers died away to nothing but smoke and ash. Dean probably doesn't even remember the date of his death. But Cas does. Because Cas was with Sam when he died and he was the one to take care of his body, wrapping it reverently and feeling very much human.

He sits on the grass now, the gloomy autumn mist surrounding him predictably. He wrings his hands as he stares at the marker, wondering what to say.

"I realize I can see you any time I wish, Sam. I can return to heaven and find you and have this conversation face to face. But I made you a promise that I wouldn't leave Dean alone. I know you never actually meant for me to follow through. Certainly not like this, after so long. And there have been days and weeks where I long to be home and I feel so guilty for thinking it."

Cas sighs heavily, angrily. "Dean's so gone, Sam. I fear there's nothing of him left. There's nothing I can say or do at this point to change him, or help him. But if I leave him, he'll destroy everything around him. There's no filter anymore. He just wants to kill, all the time. Sam, you wouldn't recognize him and I'm actually glad you're not around to see what he's become. At this point…" he swallows, an ache rising in his chest. "At this point, my only purpose is to minimize the carnage. I have to stop him. If I can't help him, I have to stop him."

He's known for a while that his mission is fruitless. He sees it every time he looks in Dean's eyes, or more closely at his soul. It might as well be a shroud, heavy and black. Once in a while a ray of light might peek through, but those moments are few and between. Now he mostly keeps an eye on him, only interfering when absolutely necessary. He doesn't tell Sam about the other times, though.

* * *

Dean's hungry, but it's not food he craves. At the moment, it's not even blood. Despite the mark, and his solitary life on the road, he still has needs. He eyes a blonde across the bar but she's not biting, no matter how long he's been checking her out. He's starting to get agitated and he downs the rest of his beer in a second, slamming it on the tabletop. He rummages in his pockets for the stolen pay card (god he misses good old fashion cash) and scans it at the machine at his table. He gets up to leave, but not before gazing over at her again. Nothing.

He swears under his breath and turns round to leave. Outside the bar he senses him. He tenses for the briefest of seconds, as he always seems to do whenever the angel is about. But just as easily, his breathing returns to normal and his pulse quickens. Perhaps this night isn't so wasted after all.

* * *

He steps out of the shadows noiselessly, even though he knows Dean is aware of his presence. Hands perpetually stuffed inside his trench coat, he raises his chin slightly in greeting.

"Hello, Dean."

For the first time in a long time, those familiar eyes glow with something alive and promising and his heart clenches painfully. He doesn't bat an eye, however, waiting patiently.

"Haya, Cas. Fancy meeting you here." The taller figure approaches, all swagger and tight jeans, hair artfully disheveled. Cas notices all this without expression. Dean's eyes, however, roam up and down his form like seeing him for the first time.

"New tie?" Dean asks with a lift of his brow. Cas looks down automatically before remembering himself, half-heartedly glaring at Dean in return. "Yes," he deadpans and tries not to stutter when Dean smirks in what could almost be a fond expression. Those days are long gone, he reminds himself darkly.

"So is it that time of the century again? Time to check up on Dean again?"

Cas barely shrugs, eyes now roaming around the vicinity. "Like you don't know I'm always checking up on you." Dean makes a sound that might be a cynical huff of laughter, but Cas can't quite decipher its meaning.

"Ah yes, you're pointless hero complex. Aren't you tired yet, Cas? I mean, really? You can't tell me you're not exhausted from chasing me around. Don't you have anything better to do with your life? Or, oh wait! Are you still barred from Heaven's gates?" he asks mockingly.

Cas clenches his jaw but doesn't rise to the bait. Again the miniscule shrug as his body slouches in repose. "I am tired, Dean. And I'm fairly aware that this whole endeavor is pointless."

"Then why, Cas? Why bother with me at all?"

Dark blue eyes glare across the short distance. "You know why."

Dean rolls his eyes to the heavens. "Oh please don't start with that bullshit again. Sam's gone so I'm not sure what you're trying to prove. So how much longer is this gonna go on for?"

"As long as I have to. If I can prevent one senseless death then it'll all have been worth it."

Dean rolls his eyes. "You know I hunt demons, Cas." He takes a step forward, eyes flashing in challenge. Cas doesn't budge.

"Not just demons, Dean. We both know you can't control your temper. And you can't control that thing on your arm."

"And you can, Cas? Control me? His tone is light but his eyes blaze with sarcasm. Castiel looks away, more annoyed than anything. "I have no wish to control you, Dean. I merely wish to protect you."

Dean laughs. "You think I need your protection?" he exclaims. "What could you possibly do for me that I can't do for myself?"

The question throws Cas off balance and Dean doesn't miss the opportunity. He smirks darkly, taking another step closer. "How long's it been, Cas? Years? Decades? Is that why you're here? Not that I mind, of course," he sidles up until he's nearly nose to nose with the angel. Castiel can feel the flush spreading across his face as he curses his mortal form. Dean smirks knowingly.

" _No_ , Dean. That is not why I'm here." He tries for nonchalance but Dean is too close, body heat radiating dangerously. His fists clench inside his pockets and he flits his eyes away from Dean's, roaming across the alleyway.

"Come on, Cas. My hotel's not far from here. It'll be just like old times."

His tone is mocking and Castiel knows Dean is toying with him but he swallows reflexively and his thoughts scatter to the wind. He's suddenly forgotten what he's even doing there.

"Those days are gone," he manages, but it sounds raspy to his own ears. He might have imagined it but there is the slightest hint of disappointment in Dean's eyes before the habitual mask returns.

"Your loss," the man declares before stepping back. "Just fucking quit following me already. It's getting annoying." He walks away from Cas, hands inside his own pockets, never once glancing back.

Cas can't deny the hum of regret resonating through him.

* * *

He doesn't get laid. In fact, after his little chat with Cas his libido hits a nose dive and he doesn't even wanna think about picking anyone up. This shouldn't happen. That poor excuse for an angel should not have that much control over him. Or any for that matter. He returns to his hotel but doesn't bother staying the night. He gathers what little belongings he has and gets the hell out of there.

With every step his blood pumps, raging, boiling. It's not the fact that Cas rejected him. It's that Dean wanted it in the first place. He should be long past all that. It makes him weak, and every time he thinks about it he feels pathetic, and he drowns in a sea of self-loathing. But the mark always makes up for it.

He can sense them. Demons. The older he gets, the stronger he becomes and his senses become sharper, clearer. It's so easy. Especially with the fledglings. They're all so twitchy. Dean loves those. Soon Cas is a distant memory once more and Dean feels like his old self.

In Alabama he sets upon a lair full of them, black eyes flashing wildly. Dean doesn't even break a sweat. He's dinged up but it was ten against one so he really made out well in the end. Cas can hide the First Blade from him all he wants, but Dean's never let the demon blade out of his sight. He cleans the blood off and strolls away.

For some reason, he doesn't feel any better. Sure it was fun, but the adrenaline soon wears off and he's left empty again. He frowns, tries to shrug it off. In the end, he gets completely drunk, mind oblivious for a few hours.

* * *

About a hundred fifty years after Sam's death, something happened to Castiel. During one of his pursuits of Dean, a sudden, blinding pain stopped him in his tracks, sending him to his knees. It felt like his back was on fire. He managed to find a public restroom and, tearing off his trench and shirt, he twisted towards the mirror, frowning at the dark redness he found on his back.

He reached back, as awkward as the angle was, and found his mortal heart stopping in his chest. With his fingertips he could just feel the small protrusions that hadn't pierced through flesh yet. Pulse racing he stood still, not really sure of what to do, or what to think. In the end, he replaced his clothing and went in search of Dean.

Hope flared through him, for the first time in over a century and it gave him the push he needed to progress on his never-ending quest. With a spring to his step, he continued on his way.

* * *

Two girls, three at a time. It doesn't matter. He never feels better afterwards. It's the same old shit. He tells them to get out before round three can commence and they are none too pleased. He reaches over to the nightstand for his open bottle of beer.

He's alone with the scent of sweat and sex and cheap perfume. He's not even tired though his body has a few nasty bruises and tears. He goes for a shower because the smell is actually getting to him. It's all wrong. It's the complete opposite of what he wants.

* * *

They grew bigger, thicker, though no mortal eye could ever tell. With each growth spurt it hurt, sending him reeling in agony. But it was the happiest he could remember being, at least in a very long time. He wondered, not for the first time, if his Father had returned. If the other angels were getting their reward as well. He didn't return to find out. His place was with Dean.

It took another fifty years before he chanced flight. Just a very short distance. He was extremely rusty with the landing, but he could have wept. They were not yet as magnificent as his old pair, but they would get there, eventually.

It was another thirty before he was able to use them for his mission. And now he is eternally grateful for the extra help.

* * *

The hand stops him cold before he can land another blow and he is flung out of the way. He lands roughly, without regard for safety. His teeth are bared like a feral dog in an instant and he's looking up at the damned tan trench that's haunted his waking steps.

The teen is already running away, conveniently healed and face a sobbing mess. Dean glares at the retreating figure before turning the look on Castiel. He's on his feet, dusting off the dry mud and grass from his favorite jeans as Castiel turns towards him, eyes brimming with undisguised anger.

Good. This he can deal with.

"How'd you find me?" Dean growls, though he's genuinely curious. Castiel of course ignores his inquiry.

"Have you finally lost your mind, Dean? He was practically a child. What were you thinking? What were you planning?"

"That _kid_ was sporting for a fight. He tried to run off with my stuff. Someone had to teach him a lesson."

"You were going to kill him."

Dean shrugs. "Who's to say. Maybe I would have beaten him until he couldn't do anything but crawl? Maybe I would have choked his little neck until his eyes turned purple? Or maybe I would have just broken his thieving little hands and left it at that? Guess we'll never know now, will we?"

Predictably, Cas' face is a mixture of disgust and anger and Dean is still itching for a fight. His quarry was unceremoniously taken from him and now he is just pissed off. The mark is itching with life, pulsating with eagerness.

"I told you to leave me alone."

He advances just as Cas leaps out of the way. Dean's having none of it. It's been way too long. He's faster than Cas anticipates, or maybe the angel's forgotten what it's like, too. Hands curl around clothing and he yanks until his other arm comes up, punching Cas right in the gut. The figure is nearly unmovable but Dean is able to get a few hits on his face and he relishes at the forming bruises and split lip.

Cas doesn't fight back. He never does. It infuriates Dean even more but no matter what he throws at him, the angel just won't raise his hands. Dean can't kill him and Cas has taken to visiting him without his angel blade, the only thing that _can_ end him, so Dean is left frustrated and bitterly angry. A raging animal.

In the end they're both breathless, one because he's constantly moving, and the other, because it's probably a punctured lung. Cas leans up on his elbows excruciatingly slow. Blood seeps from his mouth.

"Does this make you feel better, Dean?"

Yes, it does, he thinks. He feels no guilt as he stares at the mess that is Cas. It's only what he deserves. He warned him and warned him. But he doesn't say any of that. Instead, he goes for what injures Cas the most.

"I wish I'd never met you. I wish you'd just leave but I know you won't because outside of me you have no fucking life. Heaven doesn't even want you. You'd be nothing if not for me. And I don't even want you here."

His expression doesn't change, but Dean's known Cas for centuries and he knows that hurt more than anything physical Dean can produce. He doesn't spare him another glance. Breathing back to normal he gathers up his backpack and walks past the angel sitting in the dirt without looking back once.

The mark is satisfied. His gut wants to throw up.

* * *

Montana. November. It's probably cold but Castiel doesn't feel any of it. He's followed Dean here because there have been quite a few demonic disturbances in the nearby areas. There's already patches of snow on the ground and his breath comes out in wisps.

He can feel him. It's not like before, when Dean would actually pray to him, or even hope for him. It's harder to find him, but he can always sense him, more so now. The markings he engraved on his ribcage are still there of course, though they've been damaged over the decades. And with the mark raging a war over his body, it creates a barrier that is hard to fight through.

Today, he ponders on whether it's even worth it to try. It's been almost two months since his last little meeting with Dean, which left him with more than a bruised body. His pride had taken a beating as well that day. He tries to tell himself it wasn't really Dean spewing those horrid things, but it was. Dean is still Dean, mark or no. He still feels him in there.

And that's why he can't leave him.

Today is a day for self-pity, he thinks. He's entitled, he feels, after everything. But if he gives up on Dean, he'll never forgive himself. And of course, there is still Sam and the promise he made. He knows Sam wouldn't hold it against him, but he'd never be able to look at himself again without feeling like an utter disappointment.

So he follows Dean, and will continue to do so, until a time comes when something shifts, or some miracle occurs. Who knows, he thinks, a miracle has already occurred. He stretches out his wings at the thought and his mood lightens.

When the time comes, he doesn't interfere. Dean's not in any real danger. But it makes him feel better that he can keep an eye on him.

* * *

He's stopped shaving. Seems kinda pointless in the winter and he really doesn't care anymore. The less he has to do the better for him. He hates the cold, always has. He's not sure why he doesn't bother heading down south ever, but every time the weather drops and his fingers freeze from hours of walking, it just never crosses his mind. So he finds a hotel to hunker down for a while in, while his bones ache from the freeze.

Whatever good mood he's able to sustain also disappears with the cold temps. It never fails. He doesn't brood over it or anything, but he never feels like himself during the winter. Of course one would argue he _hasn't_ been himself in forever. Semantics.

Apparently he's rich for a while, given the balance on his stolen pay cards, so he finds a decent lodge and books ahead for two weeks. There's even a fireplace in his room. Old-fashioned one too, not like the new electric crap they have everywhere. It reminds him of other things. Probably best not to dwell on those.

The knock comes with surprise, the cautious rapping of knuckles, and Dean has his knife out before the sound ends. He knows who it is even without opening the door but he is wary and confused regardless.

He blinks at the sight of Cas standing there awkwardly and he has to shutter the random thoughts and memories that come with the visual.

"Hello, Dean."

He sighs and steps aside, sliding the blade in his back pocket. He doesn't bother asking why he's here. It's not like he's unaware of the disadvantages to living a solitary life. He plops down on the wide bed, runs a hand through his now longish hair.

"Cas," he says, resigned.

The angel almost shuffles uncomfortably but restrains last minute. Dean is watching his every move like he knows what he's going to do next.

"I'm aware you don't want me here. I'm not even sure why I came." He licks his bottom lip subconsciously, brow furrowing. Dean's eyes follow every movement carefully. "Sometimes I actually get nervous when I don't hear bad news," he says with a slight huff, lip curling up. "It's been months…"

Dean is up and against Cas before his brain has agreed to doing anything. His lips are firm and decisive as they press against the angel and he feels victorious when he feels the familiar arms around his back. He really doesn't want Cas to say another damned word and he's pulling him towards the bed without regard.

The mark is utterly silent. It might as well not even exist as he's pinning Cas to the mattress with rough abandon, moans drowned by rough tongues and the scraping of teeth. He's falling and he never wants to get up.

Clothing is torn off without pause and Cas' body is boiling and thrumming with a relentless energy that drives Dean insane. He doesn't allow Cas purchase but it's not like Cas can't stop Dean with a simple shove. It's like he needs this as much as Dean does.

Sweat drips liberally off Dean as he thrusts into Cas, growls and moans creeping past his lips-when they aren't attached to some part of Cas. The way the angel arches off the bed at certain moments nearly eradicates Dean right then and there. He's shocked it lasts as long as it does, what with Cas clenching onto him for dear life.

They are obliterated by the time it's all over with, though he suspects Cas has already recovered by the time Dean rolls over onto the sweat-drenched pillows. He stares up at the bland ceiling and feels a sort of calm for the first time in years.

* * *

Flushed with relief and shame, Castiel shuts his eyes in weariness. He can't contain the sigh as he scoots over to the edge of the large bed, legs dangling over the side. He sits hunched, hand coming up to rub his brow, an almost human gesture. In fact everything he feels lately is all too human for his liking. He would have embraced it once, but now it just feels all wrong.

"Sex is supposed to relieve tension," Dean quips and Cas can barely muster the sad smile he feels tugging at his lips. He heaves a sigh, not turning round. His body aches but that's impossible and yet he just wants to lie still and never get up again.

"This wasn't supposed to happen. That isn't why I came."

He hears the indignant huff. "Come off it, Cas. Don't get all high and mighty on me now. It's beneath you."

Cas smiles bitterly, though Dean can't see from his vantage point. "You are one to talk, Dean. Everything you do or say is beneath you." He hears movement behind him and Dean feels closer, his voice less muffled.

"You know what I am. What I've become. And yet you came here. You knew exactly what would happen. And you're not really sorry."

Another long sigh. "It's not so simple, Dean. This accomplishes nothing. It's almost wasteful. Tomorrow, you'll be wishing for my death." The truth of it hurts more than Cas lets on. He feels the warm, familiar wisp of breath against the back of his neck and can't stop the shiver.

"But tonight, I want you."

He doesn't turn his head, doesn't dare react, but Dean is already reaching for his waist, lips pressing against his back, his neck, so tender, it's as if he were a total stranger. He allows it all, because he has always been weak when it comes to Dean.

Teeth scrape against his flesh deliciously and he can't quite contain the growl from deep within his throat, back arching into the almost savage touch. He is taken down once more, consumed, annihilated. Oblivion finds him again for a few more hours.

* * *

Cas is gone when he wakes. Probably for the best as the mark is already pining for blood. Last night's interlude was welcome but as usual, he despises the barrage of thoughts and memories that assail him afterwards. He knows it can never be as it was. But then again, he never had Cas the way he has him now. Before, he was just his friend. Now they were not quite lovers, and certainly not friends. There is guilt/shame/anger/longing/rage and he can't sit still from all the clamoring going on in his brain.

He hates Cas for intruding into his life again. He hates himself for not being able to resist. He wants to just lie down and die already but a part of him enjoys immortality. He sighs. This is not a life. This is not living, merely surviving until the next day. Good God how did Cas manage it for centuries?

He doesn't brood long, the mark won't let him. There's work to be done, as usual.

* * *

There are parts of the United States that just never recovered from whatever plight they suffered through. Detroit is a barren wasteland, filled with dilapidated houses and skeletal remains of vehicles. Down south, hit with far too many hurricanes, is practically a swamp land, fetid and diseased. Towns were lost, long ago, to the marshes and the floods. Too costly to recover.

Castiel notices all this, now that he is able to easily get around again. It makes him despair to see how terrible conditions are, while major cities continue on as usual. True, a lot of New York City has fallen prey to the inevitable climate changes and the ocean overran the coastline. But for the most part its residents live life as best they know how.

Castiel does not like the hustle of the cities, despite his solitary life now. He doesn't want to talk to any of these busy people, or find out what sort of life they lead. He misses the people he's grown to love. He misses Sam and Kevin, and even Bobby. He misses the Dean he loved before.

It was never his intention to bring anything complicated to Dean, and even though it was Dean that first leaned in, hand fisted roughly around the lapel of his coat, it was Cas that felt the guilt of it, for decades after. Dean was not of sound mind, he should never have allowed it…

But what does that matter now? To deny the spark would be foolish, and yet every time he acts on his feelings he always feels worse afterwards. He tells himself it's for Dean. It gives him some semblance of peace and Castiel can't deny him that, not when he's been chasing him for hundreds of years, trying to aid him in whatever ways he could.

He just wishes he knew which Dean it was that kissed him, that aroused him, that wanted him. The monster that was always under the surface, or the righteous man he first met, that would die for him if he but asked. He'll always wonder, but he'll never be foolish enough to ask. He'd never trust the answer.

So to separate himself from Dean and all the dangerous thoughts that come with him, Castiel travels the land, in search of nothing and nobody, just a bit of distance.

The world has changed so much, and at an alarming pace. Sometimes Castiel isn't even aware of what's happened. It's incredible and frightening. He's certain Dean takes even less notice and if he is aware he certainly doesn't care one way or the other. There will always be people for him to kill, lives to destroy.

The mark always wants.

* * *

The blade slices through his side and he goes down. His raid doesn't exactly go as planned. Word travels fast, and when you're a demon who hears whispers of _Dean_ and the _Mark of Cain_ , well, it is only to be expected that this would one day happen.

He thinks there are about twelve, but there is actually close to twenty. And they aren't amateurs. They get him good with a head shot and he sees stars before he is pinned and a sharp, fiery pain has him grimacing with shock. He tries to fight it off. It's not like this is his first battle scar, but there are just too many of them. Blood is everywhere.

To think, he'd be one of them in a short matter of time.

But just as he is slipping into beautiful unconsciousness, a commotion starts around him and through lidded eyes he sees blinding light and hears the screech of fear. Then it is quiet.

He never passes out but he is suddenly very aware as the familiar scent of Cas envelopes him. With his remaining energy he opens his eyes and sees a fearful Cas above him. Then a soft hand is pressed to his wound and the oh-so-familiar and unwelcome feeling of flesh being seared back together wakes him back up.

Even the blood on him is gone. He sits up, feeling brand new, and glares at Cas.

"Why? Why did you help me?"

Cas is looking at him like he's a complete idiot and he gets to his feet with little effort, eyes burning into the kneeling angel. "This is what you've been waiting for, all this time. You'd never kill me yourself so all you had to do was wait for this. Why the hell would you spare my life?"

Cas gets to his feet, hair slightly disheveled from the previous fight. "You know what you would become if you died, Dean. I'd rather have you hunting as a human, not as a demon."

Dean rolls his eyes, scoffs at the irritated look Cas is throwing him. "Well I guess at this point I just don't care anymore what happens to me. I've told you before not to meddle. You don't get a say anymore as to what happens to me."

Cas is clearly restraining himself, judging by his posture and demeanor but Dean doesn't care. He just wants him to leave.

"How the hell d'you get here so fast anyway? I know you didn't follow me here."

"You think I can't find you, Dean? That I can't feel you? You think you're so far gone that you're not human anymore?"

Dean shrugs but doesn't relent. He knows bullshit when he smells it. "Still doesn't explain how you were able to get here so fast."

Cas looks away, not really guilty, but not in any mood to divulge anything at the moment. "You're welcome, by the way," Cas finally says, and walks away. Dean watches him with detachment, already thinking ahead to his next quarry.

* * *

Castiel isn't really sure why he hasn't told Dean about his wings. It's not like it affects anything. Still, there's something about the knowledge that he wishes to keep private. For now.

He's peeked in on Dean a few times since he last saw him and he never likes what he sees. It usually involves alcohol of some kind and lots of women. He's strangely not jealous. Not that he has a right to be, but he knows none of those females mean anything to Dean. They're just a diversion.

Of course he realises he's probably a diversion as well. Still, he's never caught Dean with another man. And he doesn't look at those women the same way he looks at him. He shakes the thoughts away. It's never good to think on those sorts of things and ideas. They never mean anything, anyway.

If Dean gets pleasure from using Cas, then he's more than willing to help out. This flesh, it's just an image. This body is merely a way for him to communicate, to live here on earth. If Dean admires it so much, he can do as he pleases. He'd be lying if he said he receives no pleasure from it. On the contrary, he's never felt so wanted or needed. But these are all false notions. Dean doesn't want him or need him.

Maybe he never did.

* * *

There are days when he itches for the Blade. It's a need he can never hope to achieve, what with Cas ruling over the First Blade like some king. He knows Cas will never give it back to him, not without just cause. He's too righteous for that. But on those days he's practically sweating with the urge to possess it, like the mark is punishing him for losing it so easily.

Other blades work just fine, but the First Blade is like an extension of his body. He feels incomplete without it and he wants to tear everything up around him just to get what he wants. He never talks to Cas about it because it would be a pointless conversation. No way would Cas agree to hand it over. Never in a million years. And there's nothing Dean can threaten Cas with that he'd risk turning over the blade for.

Anger overtakes him easily, and his mind goes away for a while. The other part of Dean is released to the world, seeping across the land like a plague.

* * *

Ten, twenty, thirty years. Time is meaningless for an immortal being. Castiel doesn't even know the year. He just knows he's been watching over Dean for what feels like always, and even though he can't sense the passage of time the way mortals can, he knows he is getting weary of it. Or maybe he just feels alone all the time.

It would be so easy to go home. To return to the life he once used to have. But Castiel doesn't even consider heaven home anymore and hasn't for a long time. There's nothing there for him anymore. Well, except for Sam.

He misses Sam deeply. He misses the conversations they used to have, the theories and even the laughter. It's Dean he's permanently attached to, but it is Sam that he feels sorry for. All he ever wanted to do was save his brother. His last dying thought was for Dean and he begged Castiel to watch over him. What could he say? He had already decided he wouldn't- _couldn't_ leave Dean. So he held Sam's fragile, weathered hand and spoke softly to him, promising he would do whatever it takes.

He doesn't regret it. Even when the inevitable loneliness takes over, and his mind is too tired to move forward, he still won't leave. Not after all the carnage and blood and broken bones. Not after the bitter words thrown at him, words meant to cut, to bruise. He knows the game by now. Maybe he's just self-sacrificing.

So be it.

* * *

The drumming in his mind is a relentless beat, drowning out everything around him. He hasn't slept in weeks and he doesn't even know what he looks like. Finally, he realizes, he's become one of those creatures he used to hunt long ago.

He still remembers. Still has snatches of memories from before. Wendigos and vampires and djinns and who knows what else. So many monsters. He looks down at his rust-covered hands and realizes he's just like all of them. But for some reason, the horror he is expecting at the revelation never comes. Just acceptance.

People scatter when they see him, but he barely acknowledges them. He looks for the worst parts of town and gets busy. He tells himself he's doing the world a service, ridding them of the scum and filth that inhabit it. But he can't think that deeply, not anymore.

He can't remember the last time he ate, but that's okay, he doesn't really need the food. He just needs to _feel_. His arm is on fire, burning from the inside out. The dried up blood all over him still reeks of all the different souls he destroyed, all the poor fools that happened to get in his way.

He's not even sure where he is, what state he's in. It's late evening and he's getting shady looks with each step he takes. The bar he's heading for looks older than he does and it smells just as bad. Still, if there's alcohol, he needs to be there. He's not even sure if he has anything to pay for it.

He grabs the first bar stool he sees, his lone, ragged backpack plopping noisily on the floor next to his stool. The bartender gives him a look, even as the other patrons give him a wide berth.

"'Evenin'."

Dean barely grunts a response. "Whiskey. Just bring me the bottle."

"You got funds for that?"

Dean eyes him with a steely gaze, eyes dark with promise. He can practically hear the nervous gulp the other guy takes. He smiles lazily. "Whiskey. Bottle."

"Not until I see some form of payment." He's clearly nervous but surprisingly resolute. Dean loves those types. Around him, some of the bigger fellas are starting to creep closer, eyes beady with anticipation. Dean smiles wider, though it comes off as anything but friendly.

"Buddy, I ain't gonna tell you again."

"I think you need to leave now, sir," the shaky voice utters, as the figures close around him. He doesn't even remember moving.

The stool flies backwards as he practically tackles the first body to the floor, and the fists go wild. There's chaos and noise all around. Some flee but the big ones come at him, pulling, punching, kicking. He barely feels any of it. He's crazed with blood-lust and he withdraws his blade and it feels so good in his hand he barely pauses.

He's outnumbered but it hardly matters. This is what he's wanted. This is bliss. Even the pain is dulled by the adrenaline coursing through him. His eyes sweep the space and there is just blood. Men in leather jackets, torn to shreds, boys that probably weren't even legal enough to be in a bar, sprawled in a bloody heap. He can practically feel his pulse throbbing loudly.

And he's still not finished. He wants more. Craves more. The mark's hold is absolute now, and there's nothing to stop him. He'll hack the whole fucking town to pieces, he'll hunt down anything that moves.

His thoughts don't progress further. A blinding light envelopes the entire bar, stretching to all four corners of the dingy establishment.

Cas is suddenly standing in front of him, eyes blazing an unnatural blue, searing past Dean's flesh like he's looking at him for the first time. Dean stills completely and just stares. There's something...different.

"Dean Winchester, put down that blade. Now."

Instead of obeying, Dean grips the handle tighter. He will not be bullied, angel or no. "Fuck off, Cas, I told you I don't want you here."

"Look at yourself, Dean. Look what you've become! What would Sam think?"

He loses it.

"Don't fucking say his name! He's gone, _dead_! Don't you dare come here and invoke my brother's name, not to me! Not when it doesn't even mean anything."

"You _dare._ You will not speak ill of him, Dean. You may spill blood and travel coast to coast threatening doom to everywhere you go, but you will _not_ say another word about Sam Winchester!

There is the sudden, horrifying sound of thunder clapping, so loud he nearly flinches and a light so vivid his eyes have trouble focusing, until he sees what the light all around him is reflecting. He instinctively drops his blade, the clatter drowned out by the vision before him.

The clear and unmistakable form of enormous, dark wings, spread out, splayed out across the walls and stretching to the ceiling above him. His eyes find Cas', the ethereal light flowing from his eyes threateningly.

For the first time in a very long time, Dean is truly afraid. In the back of what remains of his lucid mind, he knows he's gone too far. The image is gone almost as quickly as it arrives, and Dean is left gawking at the very familiar figure of Cas.

"You never told me," he finally utters, his voice full of wonder. "Why did you never tell me?"

The murderous expression doesn't change on Cas' face, but his posture isn't quite so threatening anymore. "You never deserved the knowledge," he sneers, and it looks all wrong on him, like he hates himself for even speaking this way to Dean.

Dean swallows and pretends that doesn't sting. The buzzing in his head is gone, filled with emptiness and about a million other things he'd rather not think about right now. His whole body wants to sag in defeat, or relief. His eyes roam around the room and he wants to throw up.

Cas, of course, can sense exactly what he's thinking. "I won't kill you but I have to stop you."

"Please kill me," he scrapes past his throat, eyes flickering back to Cas. "Please, Cas. Kill me, hack me to pieces, scatter me to the wind. There's no way I can come back from this. You have the power now. Just do it, and do it quickly, before this takes over again," he raises his arm pleadingly at Cas, whose expression flickers briefly before settling back to menacing indifference.

"It doesn't work that way, Dean. I can destroy you but the mark is infused with your soul. And I won't destroy that. I'll kill myself first."

The admission startles Dean, his protective instincts kicking into high gear. "My soul doesn't matter, Cas. I can't get into heaven knowing what I've done and I can't survive another go in hell. Even though that's only what I deserve."

Cas takes a step closer. "If I destroy the only part of you worth saving, then this whole endeavor has been for naught. I will have failed in my promise."

"Sam will understand," he begs. Cas closes his eyes like the whole ordeal pains him. When they open, they are resolute, and Dean knows he's lost.

"I told you once, centuries ago, lifetimes ago. That everyone you've ever loved would die around you and there would be no one left. No one but me. And that I would have to watch you become this monster, this thing that I don't even recognize anymore. I can see right through you, Dean. I can see every inch of you and I can hardly imagine this is the same man that I once loved."

Dean blinks away the moisture he's startled to find blurring his vision. He heaves a heavy sigh, and it hurts everywhere. "So what happens now? You won't kill me, and I can't stop myself from fighting."

Cas stares at him, a contemplative expression blooming. Dean's glad the bitterness is temporarily gone from the blue eyes. It's not a look he ever wants to see on Cas.

"If you need to fight, then fight me."

Dean's whole body is instantly flushed with warmth, and his cheeks blaze, like he's stepped too close to a fire. He gives Cas a dubious look but the angel is completely serious. It's not like he's never thrown a few punches at him. He's done it quite a few times, actually. But never with such an invitation.

"Cas," he says, trying to read anything into the impenetrable gaze. He only sees a stranger there. The old Cas he remembers has left, perhaps forever. Defeated in his purpose. Now he must deal with this Cas, this unyielding form that will stand up to Dean, no matter what. "I'm not gonna fight you. It doesn't work that way." It's true. Even as willing as Cas is, the mark doesn't respond to the invitation.

And something in Cas must realize that, because before Dean can blink Cas has him practically picked up and flung across the room. He crashes painfully into a few bar tops, bottles and glassware crunching all around him. The shock is brief, overshadowed suddenly by pure hatred. Raising himself up, scratches bleeding down his arms, he eyes the angel across the room, and the mark finally comes alive.

Ignoring the twinges of pain and torn muscle he stalks over, fists clenched. Cas doesn't budge as Dean punches him right in the jaw. He's practically immobile and Dean can feel the delicate bones in his hand protest, but he doesn't care. He starts and he doesn't stop. But this time, this time, Cas fights back.

Cas flings Dean back a few paces and hastily removes his trench coat, dropping it blindly on a corpse by his feet. He loosens his tie just as Dean flies at him again. Dean's practically foaming at the mouth as he hurls himself at the angel, who he once considered his greatest friend. He doesn't pause, or think, the mark's not letting him. It's all just pain and blood.

He knows he can't really hurt Cas, but his vessel can still bleed. His face is bruised in minutes, his left eye closing rapidly. Cas doesn't really hold back either. For the first time ever, he lets Dean feel his own wrath. He doesn't dare injure him too badly. Dean knows he'll just heal him afterwards. But he reigns upon Dean his fury, what he's been holding back for centuries.

Dean's nearly out of breath before Cas backs down, blood dripping from his swollen knuckles. He spits out a wad of blood, wiping his mouth with the back of his hand. His eyes graze all over Dean, as if assessing the damage. When he apparently feels satisfied that nothing is dire, he stands up straight, locking eyes with Dean.

"Next time you feel the urge to do this," he says calmly, indicating to the carnage all around them, "call me." He's gone in the next instant. Dean releases the shaky breath, his ribcage straining uncomfortably. He's pretty sure something's cracked or broken. Damn bastard didn't even heal him…

He manages to stand up on wobbly feet, wincing as he gathers up his fallen blade and bag. He exits the bar with as much haste as he can muster before locating a safe place to crash for the night. He leans up against some brick wall and almost immediately passes into unconsciousness.

* * *

Radio silence. Castiel doesn't actually expect Dean to suddenly reach out to him. But it's been over six months since their meetup at the bar and so far, there's been nothing. No news, no strange and violent deaths. And no prayers. Again, he isn't so naive to believe that Dean would willingly reach out to him just because he asked. But these long stretches of calm usually put him on edge sooner or later.

And so, during a blazing Minnesota summer, as he is calmly strolling through a beautiful floral sanctuary, he stops dead in his tracks as the unmistakable call for help reaches his ears. And not from any of the humans walking around him. It's not a call anyone but him can hear. In the blink of an eye he's gone.

He lands in a large hotel room in a mountainous area in what he immediately recognizes as Alberta, Canada. He mentally frowns, idly wondering how Dean even crossed the border without documentation. It seems very unimportant in the grand scheme of things.

He slowly turns to see Dean slouched at the end of the bed, eyes surprised but wary.

"Dean."

The man swallows and Cas can hear his heartbeat from where he stands, the echo a painful melody. He takes a few steps forward and he can see Dean tensing up minutely. He takes in the man's appearance and finds that not much has changed. His beard has grown longer since the last time and so has his hair, as if he's stopped caring altogether.

"What's happened?" he asks, hands casually slipping into his trench pockets. Dean gruffly coughs, like he's suddenly embarrassed he called Cas. But the look in his eyes is one Castiel recognizes all too well, and the aloofness he's been trying to maintain evaporates as he realises the nature of his call for help.

"I didn't know what else to do, Cas. It was either this or I head down to the lobby and start slashing. I tried, I really fucking tried. But this thing won't let me be and it never will. It's like it takes over and by then it's already too late. I'm hanging on by a thread here." His voice is pained as he finishes, eyes pleading, imploring.

Castiel looks him over, a million questions on his lips. Instead he slowly removes his coat, tossing it out of the way. Dean watches his movements silently before standing up, stilling Cas' hand. He reaches forward and loosens Cas' tie before deciding to discard it as well. Cas doesn't allow anything further. He punches Dean in the face.

Dean is naturally thrown back, eyes wide in surprise. He recovers quickly though, advancing on Cas like a predator who has only one goal in mind. Cas allows all this because he knows what Dean craves, what he needs. A small, selfish part of him relishes this part, though. After the events at the bar, Castiel realized he missed the old days of war and fighting. It was nice to experience a small part of it again.

Being an angel, Dean can't actually harm him, and he made sure to leave his angel blade behind, as it is the only thing that _can_ harm him, fatally even. Still, he's pretty sure Dean loves the physical aspect of it. Hand to hand combat and so forth.

They exchange blows for a short time, Dean panting heavily as he's backed up against the bed. His arms are still up but he's struggling with himself, this Cas sees plainly. So he takes the decision for him and slides one of his hands through Dean's long, sweat-soaked hair. Dean stills, eyes fluttering for a second and the haunted rage seeps away until it's just him breathing, chest heaving as Cas places his other palm flat up against it.

A strong, warm hand envelopes it. And this time it's him that's pushing Dean down upon the bed, crawling over him until he straddles his body, feeling the tension and heat the man is giving off. He grabs fistfuls of hair and grounds into Dean, marvels at the effect it has. Arms are wrapped around his torso, pulling him in, impossibly close.

When their lips meet the world ends and it's just them. Like it's always been.

* * *

"You can come back from this, Dean. Cain did."

The whisper catches Dean off guard in the stillness of the dark and his breath catches at Cas' tone. It's not pleading or desperate. It's so matter of fact Dean want to crawl in a hole and fucking cry. Even now, after all this time, Cas still believes in him. He swallows roughly, eyes up at the dark ceiling.

"I can't, Cas. I'm not Cain. I'm not strong like him. And even he broke at the end. It's in his blood. As it is in mine. I'm cursed for eternity."

"You're not, or I wouldn't be here."

Dean has nothing to say to that. He wants to dispute it because he's living proof that he's failed, and failed miserably, but he doesn't want to unsettle this moment. He's sweaty and tired but strangely content. His body smarts from all the bruises Cas inflicted but even that feels good. He lifts his head and stares at Cas' profile, eyes burning bright even in the darkness of the room.

It feels wrong, that he's brought Cas into this. It's bad enough when Cas was just helping him, aiding him. Being a friend. Now it's like he's sullied him somehow. Tainted him. He doesn't want to drag him down with him.

"You're drowning in your thoughts, Dean."

He swallows, turns away. "Get out of my head."

"I could hear you miles away, Dean. Your pain is very real and it's calling to me, always. I don't know how much longer I have before I lose you all over again to the darkness. But you're in there still, Dean. I can help you fight it off, but only you, Dean, can stop it altogether."

"I can't, Cas. Half the time I don't even realise I'm doing the shit I'm doing. It just takes over and I have no control. It's not something I can fight." He feels it even now, burning underneath his skin, boiling his blood, always churning, always wanting.

A warm hand threads through his hair and he never even heard the angel move. The touch is like a balm, a temporary relief from the real problem. But welcome all the same. He licks his lips, his heart thumping an angry rhythm in his chest.

"Cas…"

A warm body suddenly straddles him, all previous thoughts and worries scattering to the wind. Chapped lips find his in the dark and he can't prevent his arms from reaching up and around, holding on so tight he fears it would break a normal being.

But Cas is anything but. He devours Dean like it's the first and last meal he's ever known and Dean responds in kind, everything south of his stomach reacting appropriately. His mind shuts up for a while as he allows Cas to take over, obliterating him all over again.

* * *

"What are you doing in Canada?" Cas is already pristine and dressed, staring out the large hotel window, as he waits for Dean to get dressed.

"Working. Lots of logging and other dirty work to do. It passes the time, and I'm pretty good at it."

"How did you get across the border without documentation?"

Dean grins and it's so familiar, green eyes squinting, Cas pauses and just stares. "What, did you think I drove here, went through customs? There's an unbelievable amount of spots to hike through. Cold and sleep don't really affect me that much anymore, and food is more of an enjoyment now than a necessity, so I took my time to cross without much issue. I like it up here. It's quiet, not many people."

Cas nods in understanding and joins Dean by the bed. "Will you stay up here, then? Continue to work?"

Dean looks up, eyes contemplative. "I guess. Yeah I think so. Don't have many options, and they're not too picky here." Castiel places his hands inside his pockets, more so to prevent himself from reaching out and touching Dean all over again. He knows he can't stay. Sooner or later Dean will resent him all over again. Cas doesn't need to peer inside of Dean, it's written all over his soul for any angel to witness. His eyes must have been tinged with something because Dean looks up in question.

"Be careful, Dean."

A frown mars Dean's face, his eyes clouding over. "You're not staying?" Cas tries to ignore the hint of pleading he clearly hears. He shakes his head slowly. "You know it would not be wise. Right now you feel this way. In a week, a month, you will feel differently."

Dean looks away, unable to deny it. He swipes a hand through his long hair, now striped through with a dark gray, and heaves a sigh as he gets up off the bed. "Will I...still be able to reach you, in case…"

 _In case I need you._

Cas smiles but it hurts too much to keep it. "Of course, Dean. You can always reach me. And I'll always come."

Dean's clearly struggling right now and Cas hates seeing it. He steps closer until he's in Dean's space and removes his hands from safely inside his trench and instead places them on Dean's shoulders. The man is all rigid and tense and Cas just stares at the amazing greens of his eyes and the small wrinkles only now forming, and the white flecks sprinkled throughout his thick beard, and even now recognizes the man he pulled from perdition, so very long ago.

Underneath this flesh and the curse burning through his arm, the curse that may never let him go, is the man he once admired and loved, and he knows nothing's changed. As long as Dean needs him, as long as there are moments like this one, Cas will never leave him.

Dean gently pulls away, the moment over. "I gotta head into work," he says gruffly and Cas takes that as his cue. He leaves Dean with a nod, and a silent promise.

* * *

It's bitterly cold and though he hates the feeling he loves how utterly still it is. Just trees as far as the eye can see. A random house here and there. People recognize him as he walks past, giving him a warm smile or a quick wave. It's a small community here and that's how Dean likes it.

He hasn't seen Cas in a few months and is strangely okay with that. He doesn't want to come off as desperate and he's actually been feeling fine, all things considered. He's shaved off most of his beard and trimmed his hair and has gotten a few interested looks from some of the local girls. But he never reciprocates.

He's just heading towards the local bar when a loud hum overtakes his senses. A couple of guys come barreling out, shoving, grabbing. A fight must've broken out, he thinks and as soon as he sees the action, watches the scene like a slo-mo scene out of some movie, his body is flushed with heat.

 _Oh no_ , is the first thought that springs to mind, quickly followed by a _hell yeah_. His fists clench automatically and he's moving before he realizes what's happening. After that, everything is just a giant blur.

Too long, he thinks, but it's not really him. It's the _other_ him, and right now the other him is kinda pissed off. He smells blood in the air, the familiar, metallic tang that just sets him off further and deeper. He doesn't even think about reaching out to Cas. He's in the thick of things now and the euphoria is just too great.

As he's trekking back to his hotel room through the snow, knuckles bruised and bleeding, he spots a familiar shape on the horizon. He sighs, not really in the mood, but doesn't pause in his steps. When he reaches the figure, he hopes he doesn't look as guilty as he feels.

"Hey, Cas."

The disapproving glare he receives says it all and he rolls his eyes, pushes past the angel angrily.

"It wasn't my fault, okay? I didn't start anything, I was just in the wrong place at the wrong time." He isn't even sure why he's trying to defend his actions or offer an explanation. It's not like he owes Cas anything.

"Dean. Stop." The voice is dark and gravel and even now shoots straight through to the deepest parts of him, the spots where even the mark can't reach. He stills, shutting his eyes briefly before turning around.

"You gotta leave, Cas. Just, go away. I'm freaking begging you over here. I can't have you looking at me like that, and I'm going to disappoint you every time. It would be better, for both of us, if you just left. And stayed gone."

It clearly isn't what Cas is expecting and a barrage of emotions flicker briefly on his face before settling on simple confusion. "Why would you ask me to leave, Dean? I told you I would help you."

"I don't want your help, Cas," he grits out, dangerously approaching the point of no return. "Nothing you can do will make this go away. And no offence, but I don't need you to get laid, either, I got plenty of willing options."

Cas' eyes flash with resentment, or betrayal, Dean's too far gone to recognize either. He wants to stop the flow of words, but he's fading already, something more powerful is already taking over. He tries to hold on to what he sees before him, tries to look at Cas and will himself to remember. But it's slipping from his grasp like sand, slowly filtering out.

Cas must've seen the subtle transformation and Dean is already prepared for the fight. But what comes out next is not what he expects.

"But what if I need you?"

Dean gawks, not comprehending. His head hurts and his whole body is burning up, trying to stay lucid enough to hear what Cas has to say. The angel takes a few steps closer.

"What if you're the only thing I have holding me here? What if helping you helps me? I don't even know if I can be an angel anymore, Dean. I've been here too long, been with you too long. You want me to go? Where? Back home? To Heaven? I don't have a place there anymore, Dean. There's nothing there for me. You think I'm here simply because Sam asked me to be? You think I'd devote centuries to watching you murder your way across the country? It's all for you, Dean. Because you've never thought you were special, or you deserved anything. You always kept everyone at an arm's length, including me. Well there's nowhere else to go, Dean. For either of us."

Dean can only stare, his heart racing, his mind in turmoil, and the mark blazing on his arm, threatening to turn him into a monster. But all he hears is the sorrow and conviction in Cas' words. He's shaking with tension, fighting to hold on, to stay pure. He lick his lips with effort, but Cas stalls him.

"If you truly feel this way, I'll go away. But I think I know you better than that, Dean. I raised you up and I pieced you together, body, mind and soul. I _know_ you. And when you call me, I will come to you."

Dean is left staring at an empty, snow-filled road, no angel in sight. He blinks as the sun sets over the horizon and he releases his pent-up breath in a whoosh of mist and air.

Everything hurts. Maybe it doesn't have to hurt so much.

* * *

Castiel wanders for weeks, until they blur into months. He never tires, except of the mundane and he's even started conversing with people. It keeps the boredom at bay. He roams the cool beaches of the northern Atlantic and the bright, endless blues of the Pacific. It's all very picturesque.

He tries not to dwell on anything related to Dean; it isn't very good for him. Even though he is immortal, and an angel at that, he finds his chest constricting unpleasantly whenever he imagines Dean in any particular way. It's uncomfortable, this sensation, like he's missing something and he's empty without it.

He's too used to this body now, too accustomed to its wants and needs. Though he doesn't require food or drink, he indulges once in a while, and finds he enjoys it more than he did. He refuses to indulge in anything else. The thought revolts him and sends him into a shame-filled spiral for even considering it.

He misses Dean every day. And no matter how long he goes without seeing his face, he will miss him always. And when he feels the familiar tug pulling him towards his one and only desire, he can't repress the spark of joy that blooms where the empty feeling in his chest was. He stretches out his wings and takes flight.

When he lands outside a cheery diner in Oklahoma, he almost thinks he's got the wrong spot. But the whisper is still calling to him, paving his way forward. He goes inside and hardly anyone gives him a glance. It's when he peers towards the booths in the back does his heart stop.

Dean is there, patiently waiting for Castiel to walk over to him, and he's shaved his beard and cut his hair and it throws Cas off balance, like he's gone back in time. With slow, measured steps he approaches, disbelief radiating off him, until he is standing by Dean's booth, mouth slightly parted.

Dean's eyes are bright, and he gives him a shy smirk, like he's not quite sure what to make of Cas staring at him. The angel doesn't say a word as he slides in the seat opposite.

"Hello, Cas."

His heart is doing some rather vigorous acrobatics inside his chest and he knows he's still staring like a loon and Dean's grin is getting wider, eyes crinkling with amusement and it's like deja vu all over again. Cas swallows, feels a strange clogging sensation in his throat.

"Dean," he finally manages but it comes out wrong, judging by the small frown forming on Dean's brow.

"You okay, Cas?"

No, he is certainly not okay. He isn't quite sure what is happening and he's pretty sure there's something off with his vessel as his vision is suddenly obscured. He tries to blink the strange film away only to feel a light wetness trailing down his cheeks.

Dean is staring at him now with something akin to shock, and worry is etched in every wrinkle. "Cas," and he is suddenly reaching forward and a warm thumb is grazing across his cheek, sweeping away the wetness still lingering. He looks down at his finger, then again at Castiel's face.

"I thought angels couldn't cry," he simply says with a hint of confusion and worry, eyes grazing over Cas' face, carefully inspecting. Castiel at first doesn't understand the query but then he too slowly reaches up to feel the strange liquid, some still coating his lower lashes. He looks at the substance in wonder.

"They... _we_ shouldn't be able to." He swallows thickly, trying to understand why this was happening. "I don't...feel sadness," he frowns at Dean in question. The man's face turns from concerned to endearing.

"Cas, sometimes people cry because we're overwhelmed, or happy or just because sometimes it's just too much," he explains. He looks down at the table. "I guess I do look a bit different."

"What happened?"

Dean is hunched over the table, a coffee mug steaming in front of him. He idly toys with the rim, running his finger along the edge before shrugging in answer. "You happened," he simply says. "Whenever you were around I wanted to rip your throat out and whenever you were gone I wanted to die from needing you. I don't have a better answer. It's just how I feel. Or felt rather."

Cas doesn't react to the admission. He places his hands on the table, folded together, and leans forward. "And now? What's changed?"

Dean's vivid green eyes find his and there's shame there, yes, but also determination and resolve. "You didn't come back. And you stopped following me. I could feel the absence and that was worse than anything I'd felt up till then. I always had you, even though I loathed your presence and your meddling. You were a constant, just as much as my mark is. I couldn't shake off either of you. And when I knew you'd actually left, I thought I'd be more pleased. Instead, I panicked." He looks away, licking his lips and Cas follows every movement.

"You told me I could fight it, like Cain did once. I didn't believe you but I got to thinking, when Cain stopped, it was because he too was told he could stop. Collette. His lover. She begged him to stop and he did. He did it for her. I thought, if he could just stop, then I could too. But I needed someone to tell me I could. I still need someone to tell me." His eyes find Cas and they're determined but filled with doubt, always doubt, and Castiel can't stop the strange pain from blooming inside his chest.

"I've told you before," he starts, voice clear and purposeful, "I believe you can do this, Dean. And I will keep telling you as long as you need me to. I will not let you falter."

Dean swallows reflexively, eyes never leaving Cas' face. "Stay with me."

It's more of a plea than a question and Cas can hardly fight the urge to throttle the stupidity from this man. "Of course I'll stay with you," he whispers with a mild smile. Dean looks slightly relieved, before turning pensive again. He swipes a hand through his shorn hair.

"You know I'm no good for you, Cas. You know I'll probably have more bad days than good ones. I can't promise you anything. Hell I can't even promise I won't turn on you again. I just know that you're the only thing that can actually give me a fighting chance here. I'm a mess, Cas. Hell was a cakewalk compared to this."

Castiel gives him a solemn look, his angel eyes piercing through Dean's flesh, straight to the source. What he finds there gives him hope. "Dean, you are not a mess. I promise you that. You can't see what I see. What you've managed to do in a short time is miraculous, and it shows on your soul. I see light overshadowing the darkness that's there."

Dean shakes his head like he doesn't want to believe it. "All those people, Cas, all those people I've...destroyed. What of them? I can't ever make that up, not ever."

"I know you don't want to hear this Dean, but you know it wasn't you. You said it yourself, you were hardly aware you were doing it. This...curse engulfed you and molded you into something we both know you're not. You're a hunter, it's in your blood. The Mark took it further. It fed off your drive and removed your humanity. But you came back. You can't look behind you, Dean. For this to work, you have to look ahead."

"You'd still be willing to do this with me, Cas? After everything? You're willing to just forget it all?" Dean asks incredulously. Castiel takes a moment to answer, because he has thought long and hard about precisely this. "I will never forget, Dean. Just as you won't. But my desire to help you, to aid you, will always overcome that. You've always been my friend, Dean, whether you remember that or not. I would die for you if it would but rid you of this destiny. But I can't, so I will do all that it is in my power to do to help you."

Dean looks miserable, though it is not Castiel's intention. He wants to reassure him once more but he knows it will take more than just this one act of faith. He clearly has many doubts and Castiel knows it will take time to rebuild the trust that they once used to have. But they have all the time in the world.

End.


End file.
